LITTLE ROCK (AP) — Former U.S. Rep. Mike Ross on Wednesday made his bid for Arkansas governor official, criticizing his chief Republican rival over ads being aired by an outside group and for not weighing in on the debate over the state's compromise Medicaid expansion.

Filing paperwork at the state Capitol, Ross vowed to follow in the footsteps of Democratic Gov. Mike Beebe as he seeks the state's top office. Ross is the only announced Democratic candidate for governor, with Beebe unable to seek re-election because of term limits.

"Today I'm here to tell the people of Arkansas that my desire to serve has never been greater," Ross said after filing. "I'm committed to leading this state, to build on the foundation that Gov. Beebe has laid and make sure this state does not turn back."

Ross criticized his main GOP rival, former U.S. Rep. Asa Hutchinson, over television ads the Republican Governors Association is airing criticizing Ross as being too closely aligned with President Barack Obama and House Democratic Leader Nancy Pelosi. Hutchinson, who lost the 2006 governor's race to Beebe, and Little Rock businessman Curtis Coleman filed Monday to run for the GOP gubernatorial nomination.

"I think it's a reflection that Asa Hutchinson, before he even filed for governor began a very desperate campaign that's being funded by his wealthy, out of state special interest friends who are going to continue for the next eight months to misrepresent the facts, distort the truth and lie about me and my record," Ross said.

The former congressman also criticized Hutchinson for not wading into the debate over whether Arkansas should keep the "private option" that was approved last year as an alternative to expanding Medicaid under the federal health care law. Under the private option, Arkansas is using federal Medicaid funds to purchase private insurance for thousands of low-income residents.

The program is at risk, after its funding bill has stalled before the state House. Ross said he supports the private option and said lawmakers need to keep the program, which is providing subsidized coverage to more than 93,000 people. Debate over the program has sharply divided Republicans, who control the state Legislature.

Hutchinson on Monday again declined to say whether the Legislature should reauthorize the program, saying "the last thing they need me is to be holding a news conference and telling them what to do." Coleman has called for the end of the private option.

"It looks like to me he's trying to conveniently pick and choose which issues he takes a position on," Ross said.

A spokesman for Hutchinson's campaign called Ross' comments on the RGA ads "the height of hypocrisy," saying it had nothing to do with the spots but arguing they accurately depicted Ross' votes. The RGA spots criticize Ross for several votes, including his support of the 2009 stimulus package and the auto bailout in 2008.

Christian Olson, Hutchinson's policy and communications director, defended Hutchinson for not weighing in on the private option debate.

"Congressman Ross needs to remember that we would not be in the situation that we are now had he stopped Obamacare when he had the chance," Olson said in an email. "We have one governor at a time and the last thing the Legislature and the governor need are candidates playing politics on issues. Asa has remained consistent in his opposition to Obamacare."

Ross voted for a House version of the health care overhaul in committee in 2009, but voted against the measure that President Barack Obama signed into law. Ross also later joined with Republicans to vote for repealing the federal health care overhaul.

Other candidates filing Wednesday included state Rep. Debra Hobbs, who dropped out of the governor's race to seek the GOP nomination for lieutenant governor. State Rep. Duncan Baird, R-Lowell, and Democratic hopeful Karen Sealy Garcia, a Hot Springs City director, filed to run for state treasurer.

Hot Springs businessman Tommy Moll filed to run for south Arkansas' 4th Congressional District and Republican state Rep. Andrea Lea of Russellville filed to run for state auditor. Republican David Sterling filed to run for attorney general.

The weeklong filing period for state and federal office in Arkansas ends at noon March 3.